The suburbs emerged after WW2 to further enmesh white petty bourgeois and wealthier elements of the white working class into the imperial capitalist system. White flight was an opportunity; it offered these comfortable white cohorts a chance to become property owners and to escape the increasingly Black and Latine urban cores, which they associated with crime, violence and poverty.
Your Freddy Kreugers, your Friday the 13ths, your Stranger Things are all that violence coming back to pierce the suburban facade of homogenous safety. They're expressions of white petty boug' (and labor aristocracy's) fear of The Other, and a warning that the world past Elmdale Lane is hostile and best left unexplored.
It could very well go the "it's just portraying things not condoning them" angle, because some people just can't accept others stating that the things they enjoy could have questionable or even propagandistic elements.